Goals: The overall goals of this application are to examine the role of a the 13-catenin-Lef signaling pathway in contributing to the alterations in gene expression associated with acute renal injury and to elucidate the role of this pathway in modulating events associated with recovery of renal function. Specific aims Each specific aims will test one of three interrelated hypotheses: Specific aim 1: To test the hypothesis that ATP depletion-repletion activates the Beta-catenin Lef pathway in cultured proximal tubular cells. Specific aim 2: To examine our hypothesis that ATP depletion-repletion results in beta-catenin-Lef mediated activation of gene expression. Specific aim 3: To test our hypothesis that the Beta-catenin-lef-1 pathway alone or in association with NF-kappB inhibits apoptosis induced by ATP depletion-repletion. Long-term goals: To elucidate the mechanisms involved in the process of recovery and repair from acute renal failure (ARF). Significance: Elucidation of the mechanisms involved in recovery and repair may lead to insight that facilitate the development of therapeutic interventions that promote recovery from ARF.